DESIGN AND APPLICATION OF SUPERHYDROPHILIC/SUPERHYDROPHOBIC SURFACE USING NANOHONEYCOMB STRUCTURES

DoctorFor many years there have been efforts to increase fluid flow under certain constraints. And A variety of two-dimensional (2D) superhydrophobic surfaces have been fabricated for biological and industrial applications. We first introduced a three-dimensional tube structure with a superhydrophobic surface based on an AAO/Al wire template and dipping. Our fabrication method is simple, economical, and reproducible. Moreover, this method can be extended to other complex 3D shape structures for various purposes. For the drag reduction, the superhydrophobicity of the PTFE nanofiber forests was investigated, resulting in the CA of 170？a, the sliding angle less than 1？a, and the CAH of 2？a. We further demonstrated the improved mass flow (up to 65 %) in the tube structure with nanofiber forests due to the high CA and low CAH. The method might successfully be used to prepare 3D structures with surperhydrophobic surfaces from a wide variety of materials and can be utilized for potential applications such as thermal heat sinker and artificial vessels.A variety of flat superhydrophilic surfaces have been fabricated for biological and industrial applications. We have fabricated a surface that undergoes ¨complete wetting〃, by means of dual-scale surface modification. The first stage is plasma etching, which generates microscale unevenness on the aluminum surface. The resulting plasma-etched aluminum surface was then anodized. The anodized aluminum oxide surface contains nanoscale hole structures. The resulting dual-scale surface was like the reverse side of the lotus leaf, having superhydrophilic properties and a near-zero contact angle. This is the result of a synergetic effect between the two fabrication processes, which greatly increases the capillary force. Our dual-scale surface can be used in torpedoes, and in heating/cooling-related consumer and industrial products to act as an effective condensation surface which selectively and efficiently collects moisture. Since aluminum is the most common material in many of these products, the present method is applicable with no further material costs. Moreover, this method can be used with other materials which can be anodized to form nanoscale holes. A superhydrophobic surface has been fabricated, using industrial aluminum plate, by a simple process. This superhydrophobic surface prevents cell attachment. It exhibited excellent repellency and low adhesion properties, whereas the aluminum surface and the PTFE surface were stained by large numbers of nuclei. The difference is due to the surface tension, hydrophobicity and geometry of the surface. Cell adhesion to a superhydrophobic surface is largely inhibited by the water repellency of this surface, which prevents the penetration of cell solution. This superhydrophobic surface may find application in clinical therapy, due to the anti-cell adsorption properties. Also, this surface is available for application to bioseparation devices, microfluidic devices, liquid transportation without loss, and related technological problems.Wettability is important in industrial applications and remains the subject of theoretical research. Surfaces are described as superhydrophobic if their water contact angle (CA) is greater than 150？a, and superhydrophilic if the CA is less than 10？a. We have successfully fabricated any desirable patterning surface having superhydrophobic and superhydrophilic properties on a co-planar surface by a plasma polymerization with hydrophilic acrylic acid on the nanofibers structures with suprhydrophobic property. Furthermore, the plasma deposited surface maintains superhydrophilicity even after storage in air for forty five days, confirming that these structures are stable and reliable. Our fabrication method is simple, economical, and reproducible. Moreover, this method can be extended to 3D shape structures for various purposes because of flexibility. Such a co-planar surface with a superhydrophobic and superhydrophilic property could be a potential platform for many applications such as conductive nanowires synthesized, formation of a self assembled layer, and microfluidic devices for biological studies